Boat fender



' March 3, 1970 h v I LJDEAN f'BoA'r FENDER wmr rnruwligdnlig 2 Sheets-Sheet 1 INVENTOR. [yr/L flaw I BY I 1 1,... r. l" I i n: n. n n

Filed April 26, 1968 March 3, 1970 0.1.. DEAN BOAT FENDER 2 Sheets-Sheet 2 Filed April 26, 1968 IIIIII '1 I N VENT OR. i; A 2544/ I &

' yaw/w AffUZl/EPS United States Patent O U.S. Cl. 11421 16 Claims ABSTRACT OF THE DISCLOSURE A structure permitting construction of large, relatively light boat fenders that do not deform substantially in the course of use. A first block of buoyant material is enclosed within an inner supporting bag. A second block of buoyant material is contiguous to the inner bag. The blocks each have two parallel sides, the parallel sides of the second block being arranged in parallel relationship with the parallel sides of the first block. An outer supporting bag encloses the second block and the inner bag. In this fashion, more blocks of buoyant material can be added to provide a thick boat fender without deformation of the structure. The open ends of each bag are clamped together between bars running the length of the top of the structure.

CROSS-REFERENCE TO RELATED APPLICATIONS This is a continuation-in-part of a copending application, Ser. No. 616,373, filed Feb. 15, 1967, now aban doned.

BACKGROUND OF THE INVENTION This invention relates to boat fenders and, more particularly, to a new structure for a buoyant, preferably water-tight boat fender.

For many years cocoa and rope mats, pieces of cork,

and solid nonporous rubber have served as boat fenders. These structures have proved useful to reduce or eliminate damage upon collision of two boats or a boat with a dock by absorbing the impact in part and distributing it over a larger area, but they suffer from numerous shortcomings. For the most part, these fenders absorb water are nonbuoyant and subject to fast wear, and lack the ruggedness and resiliency to withstand for extended periods of time the tremendous impacts that are encountered in normal use.

Recently a boat fender structure has been developed that overcomes these shortcomings to a large extent. This structure comprises a hollow, rubber core around which sheets of buoyant resilient material are wound in the form of a spiral and cemented together. The resulting cylindrical body is bagged, so to speak, in a snug-fitting watertight cover. Fixtures mounted at either end of the structure are connected by a steel cable running through the hollow interior of the core. In use these fenders are draped over the hull of the boat by lines secured to the fixtures. This fender structure has found wide acceptance because it is watertight, buoyant, rugged, and resilient. In addition, it is fire-resistant and is easy to clean and repair beacuse of the watertight cover.

My Patent 3,455,269, which issued on July 15, 1969, to the assignee of the present application, discloses and claims several features that make the cylindrically-shaped boat fender more versatile.

SUMMARY OF THE INVENTION The present invention contemplates a structure permitting the construction of large boat fenders that have a ICC large impace surface and do not deform substantially in the course of use. A first block of buoyant material is enclosed within an inner supporting bag. A second block of buoyant material is contiguous to the inner bag. An outer supporting bag encloses the second block and the inner bag. Preferably, a third block of buoyant material is also enclosed within the outer bag on the other side of the inner bag from the second block. This results in a symmetrical structure. Each block has two parallel sides. The blocks are arranged in the structure with all these sides in parallel relationship to one another and to the impact surfaces. To expand the structure further, more blocks of buoyant material are added in similar fashion. In each case, a supporting bag encloses the newly added blocks and the already existing structure. The final structure comprises a plurality of supporting bags one within the other, each containing one or more blocks of buoyant material lying parallel to one another.

The open ends of the supporting bags are individually clamped between bars running along the length of the fender. Connecting rods hold the bars in clamping relationship. In use, the (bagged blocks hang under the bars, which are secured to the boat by fixtures.

BRIEF DESCRIPTION OF THE DRAWINGS The features of specific embodiments of the invention are illustrated in the drawings, in which:

FIG. 1 is a side elevation view in section of one embodiment of a boat fender incorporating the principles of the invention;

FIG. 2 is a top plan view of the fender of FIG. 1;

FIG. 3 is a front elevation view of the fender of FIG. 1;

FIG. 4 is a side elevation view in section of another embodiment of a boat fender incorporating the principles of the invention;

FIG. 5 is a front elevation view in section of the fender of FIG. 4; and

FIG. 6 is a top plan view in section of a fender of FIG. 4.

DESCRIPTION OF SPECIFIC EMBODIMENTS In the embodiment of FIG. 1, blocks 1, 2, 3, 4, 5 and 6 of buoyant material are shown. Each of the blocks 1 through 6 has at least two parallel sides, namely the vertical sides in FIG. 1 that are perpendicular to the plane of the drawing. In the usual case, the blocks would be a rectangular solid, as represented in the drawing, but they could also be configurations other than rectangular. Preferably, the cross sections of the blocks in planes parallel to the parallel sides are all congruous with one another as shown in the drawing. A suitable buoyant material is, for example, a closed-cell polyvinylchloride foam material such as Type AF Ensolite marketed by the United States Rubber Company. The rectangular blocks are built up from thin slabs of the buoyant material that are cemented together side by side. Each block could be formed from a single piece of material if material of sufiicient thickness is commercially available. Block 3 is enclosed in a supporting bag 7, and block 4 is enclosed in a supporting bag 8. Bags 7 and 8, which are contiguous with one another, constitute the center of the boat fender. A single bagged block could replace blocks 3 and 4, as the center of the boat fender.

Blocks 2 and 5 are contiguous to opposite outside surfaces of bags 7 and 8, respectively. Thus, the parallel sides of blocks 2 and 5 abut the parallel sides of blocks 3 and 4, respectively. A supporting bag 9 encloses blocks 2 and 5, as well as the already existing structure, namely bags 7 and 8 with their contents. Blocks 1 and 6 are contiguous to opposite outside surfaces of bag 9. Another supporting bag 10 encloses blocks 1 and 6, as well portion of the as the already existing structure, namely bag 9 and its contents. In similar fashion, the thickness of the boat fender can be expanded by adding more blocks of buoyant material and enclosing each newly added block and the already existing structure in another supporting bag. In each case, the blocks are preferably the same length (vertical dimension in FIG. 2) and height (vertical dimension in FIG. 1). They are also arranged with their vertical sides that are perpendicular to the plane of the drawing (FIG. 1) abutting and lying in parallel relationship to one another and to the impact surfaces of the boat fender.

The supporting bags could be sheets of crossed nylon tire cord coated with neoprene and cut to form a snugfitting cover of either oneor two-piece construction. If the bags are of two-piece construction, one piece could extend down one vertical side of the block, along the bottom, and up to opposite vertical side, while the second piece extends down one vertical side perpendicular to the first two sides, along the bottom, and up the opposite vertical side perpendicular to the first two sides. The seams of the pieces could be sealed with rubberized adhesive tape.

The two free ends of each of bags 7 through 10 parallel to the length of bars through 22 are clamped between bars 15 through 22, as illustrated in FIGS. 1 and 2. The ends of the contiguous sides of bags 7 and 8 are clamped together between two bars (18 and 19), but the other ends of bags 7 through 10 are all clamped individually between two bars. Bars 15 through 22 are held in parallel relationship against the ends of the bags by threaded connecting rods 23. Bolts are tightened down on either end of connecting rods 23 to maintain the clamping action on the bags. The two free ends of each of bags 7 through 10 perpendicular to the length of bars 15 through 22 are simply bonded to the ends of the respective bars. It is not necessary to clamp these free ends because the other two free ends of the bags, i.e., the free ends of the bags parallel to bars 15 through 22, carry the weight of blocks 2 through 6 in the same Way that a sling supports its load. In FIG. 1, the vertical spacing between bars 15 through 22 and the tops of blocks 1 through 6 is exaggerated. This vertical distance would be much smaller in practice relative to the height of the blocks than actually depicted in FIG. 1. A steel cable 24 is attached to both ends of one connecting rod, while a steel cable 25 is connected to both ends of another connecting rod. Steel cables 24 and 25 are each clamped at their ends between a bolt and the adjacent bar and pass through a ring 26 near their centers. In use, the fender is draped over the hull of the boat (designated 30 in FIGS. 2 and 3) by lines secured to ring 26, so the length of bars 15 through 22 extends substantially parallel to the hull of the boat. Thus, large, flat impact surfaces are provided for colliding ships.

Outer bag 10 in the embodiment shown in FIGS. 1, 2, and 3 is not watertight. It is not essential for a watertight fender that the outer bag be watertight because the foam from which the blocks of buoyant material are made has closed cells and therefore absorbs little or no water. In other words, the buoyant material itself is preferably Watertight. The advantage of having a watertight outer bag is that oil and other foreign substances are prevented from penetrating into the interior of the fender. Foreign substances remain on the surface of a watertight bag where they can be easily washed off.

Since each block of buoyant material is supported directly by its bag whose ends are clamped between steel bars, thick boat fenders can be constructed without causing the bottom of the fender to deform or sag. Typical. dimensions for such a boat fender are a length of 7 feet (the dimension parallel to the length of bars 15 through 22), a thickness of 10 feet (the horizontal dimension perpendicular to bars 15 through 22), and a height of 5 feet. The thickness of each block could be 15 inches. A boat fender with these dimensions would weight approximately 2 /2 tons, which is relatively light for a body of such large volume. In use, the fender is subjected to most of its force on the impact surfaces in a horizontal direction perpendicular to bars 15 through 22. The structure is particularly well suited to withstand force in this direction because in this dimension the supporting bags break the buoyant material up into a small individually held blocks.

In FIGS. 4, 5, and 6, an embodiment is shown that has a watertight outer bag. Blocks 41, 42, 43, 44, and of buoyant material, which are located one next to the other, have side covers 46, 47, 48, 49, 50, and 51, respectively. Side covers 46 through 51 are elongated lengths of neoprene-coated tire cord wrapped around and cemented to the surface of the blocks. As illustrated in FIG. 5, each side cover extends from the top of a block, down one side of the block, across the bottom of the block, up the other side of the block, and across the top of the block so the ends of the side cover overlap along a surface designated 52. The overlapping portions of each side cover are beveled and cemented to one another. As illustrated in FIG. 6, the side covers are wider than the blocks around which they are wrapped and their longitudinal edges are folded over the corners as designated at 53 and cemented to the front and back surfaces of the block. Slings and 61 are wrapped around blocks 42 and 43, respectively. A sling 62 is wrapped around blocks 41 and 44 and slings 60 and 61. A sling 63 is wrapped around blocks 40 and 45 and sling 62. Slings 60 through 63 are also elongated lengths of neoprene-coated tire cord that are cemented to the portions of the fender that they contact. The cords run parallel to the length of slings 60 through 63 and side covers 46 through 51. Each sling extends from a point on the top of the fender, across the top of the fender, down the front surface of one of the blocks, across the bottom of the fender, up the back surface of one of the blocks, and across the top of the fender, as illustrated in FIG. 4. The ends of slings 60 through 63 are clamped between steel bars 64 and 65, which are held in parallel relationship against the ends of the bags by a plurality of threaded, connecting rods such as that designated 66. Thin, steel plates 67, 68, 69, 70, 71, 72, and 73 are sandwiched between the ends of the slings to prevent the connecting rods from tearing them under the weight of the fender. Plates 67 through 73 are cemented to the ends of the slings. The connecting rods pass through holes in bars 64 and 65 and plates 67 through 73. Bolts are tightened down on either end of the connecting rods to maintain the clamping action on the bags. As in the embodiment of FIGS. 1, 2, and 3, steel cables are attached to both ends of two of the connecting rods to provide a fixture for securing the fender to a boat. Slings 60 through 63 are drawn taut by the clamping action of rods 64 and 65, even when the fender is resting on a surface that supports it from underneath. Due to the tire cords, slings 60 through 63 do not stretch appreciably when the fender is supported from above while it is draped over the hull of a boat. Therefore, the portions of slings 60 through 63 extending across the top of the fender remain cemented together and to the tops of the blocks at all times. In summary, side covers 46 through 51 and sling 63 completely seal all of blocks 40 through 45 from the exterior of the fender, thereby serving as a watertight outer bag. Slings 60 through 63 serve to support the blocks in the same fashion as the bags in the embodiment of FIGS. 1 through 3.

As a final step in the construction of the described fenders, they are heated under pressure so that the various parts fuse together. This causes the neoprene from the overlapping portions of the bags to fuse together to form a watertight joint. The pressure could be provided by encapsulating the fenders in steel drums during heating. The drums confine the fenders to their original size as the buoyant material expands in the course of the application of heat, thereby generating pressure.

For the purpose of illustration, the neoprene-coated tire cord in the drawings is depicted at being much thicker relative to the size of the blocks of buoyant material than is in fact the case. Thus, the dilferences in thickness in slings 60 through 63 depicted in FIG. 4 would actually be quite small.

What is claimed is:

1. A boat fender comprising: a first block of buoyant material having at least two parallel sides; a first supporting bag enclosing the first block; a second block of buoyant material having at least tWo parallel sides, the second block being contiguous to the outside surface of the first bag such that one of its parallel sides abuts one of the parallel sides of the first block; and a second supporting bag enclosing the second block of buoyant material and the first supporting bag.

2. The boat fender of claim 1, in which means are provided for separately holding each bag.

3. The boat fender of claim 2, in which each bag has an open end above the enclosed blocks, and the bag holding means comprises a plurality of parallel arranged bars between which the open ends of the bags are individually clamped and a plurality of connecting rods retaining the bars in clamping relationship with the bag ends.

4. The boat fender of claim 3, in which cables are attached to the ends of each of a plurality of the connecting rods and each of the cables passes through a ring.

'5. The boat fender of claim 1, in which a third block of buoyant material having at least two parallel sides is provided; and a third supporting bag encloses the third block of buoyant material, the third bag being contiguous to the first bag and enclosed by the second bag such that one of the parallel sides of the third block abuts one of the parallel sides of the first block.

6. The boat fender of claim 5, in which a fourth block is enclosed by the second bag, the fourth block being contiguous to the third bag such that one of its parallel sides abuts one of the parallel sides of the third block.

7. The boat fender of claim 6, in Which each bag has an open end above the enclosed blocks, a plurality of parallel arranged bars individually clamp the open bag ends, and a plurality of connecting rods pass through the bars transverse to their length to retain the bars in clamping relationship with the bag ends.

8. The boat fender of claim 7, in which the clamping relationship is maintained by bolts tightened down on the ends of each rod.

9. The boat fender of claim 1, in which a third block of material having at least two parallel sides is provided, the third block being enclosed in the second bag on the opposite side of the first bag from the second block with one of its parallel sides abutting one of the parallel sides of the first block.

10. The boat fender of claim 1, in which the blocks have congruous cross sections in planes parallel to the parallel sides.

11. The boat fender of claim 1, in which a plurality of additional blocks of buoyant material having at least two parallel sides are provided, each of the additional blocks being enclosed in an additional supporting bag together with the blocks already enclosed in their respective supporting bags; one of the parallel sides of each of the additional blocks abutting one of the parallel sides of another block.

12. The boat fender of claim 1, which is draped over the hull of a ship such that the parallel sides of the blocks are substantially in parallel relationship with the surface of the hull of the ship.

13. The boat fender of claim 1, in which the first and second supporting bags each comprise a watertight side cover that is wrapped around four sides of the block it encloses and a watertight sling that is wrapped around four sides of the block it encloses including the sides excluded by the side cover, the sling and the side cover overlapping in sealed relationship to form a watertight bag.

14. The boat fender of claim 13, in which means are provided for clamping the ends of the slings together.

15. The boat fender of claim 11, in which the first and second blocks and the additional blocks are all solid, rectangular masses of buoyant material.

16. The boat fender of claim 1, in which the first and second blocks are solid, rectangular masses of buoyant material.

References Cited UNITED STATES PATENTS 2,606,755 8/1952 Samuels 267-1 3,033,151 5/1962 Sheehan 114 219 FOREIGN PATENTS 479,078 1/1938 Great Britain. 637,606 5/1950 Great Britain.

MILTON BUC'HLER, Primary Examiner JAMES E. PITTENGER, Assistant Examiner US. Cl. X.R. 61--48 

